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Big block 4.150 stroke 2.375 rod 4340 crank? #1712481
12/18/14 07:37 PM
12/18/14 07:37 PM
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Vidor Texas
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onyxba Offline OP
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What crank would you run, eagle, scat, molnar. ohio crank. Drag race 750 to 800 horsepower? Thanks for any reply's.

Re: Big block 4.150 stroke 2.375 rod 4340 crank? [Re: onyxba] #1712482
12/18/14 07:43 PM
12/18/14 07:43 PM
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Whatever would fit in an aftermarket block.

Unless you have a set of really nice aftermarket rods that use that pin there is NO REASON to use the big crankpin. As you are trying for big power why not go directly to a 4.25 or 4.375 or even 4.5" crank and the 2.2 pin? Selection improves greatly. Plus you don't have to turn the motor so tight.

R. my

Re: Big block 4.150 stroke 2.375 rod 4340 crank? [Re: onyxba] #1712483
12/18/14 07:44 PM
12/18/14 07:44 PM

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any will work but some have certain cranks in 8 bolt flange only so don't get caught on that
I love Scat cranks but freight from west coast to east coast means we use lots of Eagle--Never a failure and we beat the snot out of them Honest the Eagle has been refined over the years and is a very good unit--need more? Go Callies and sleep better--get a polished unit that looks like Jewelry but... $$$$$$ Eagle can take a beating--800HP on one is no big deal at all---and.....is available NOW Todd at Marsh Performance will ship you one today for a very good price--!!!!!!!!!!!!!!!!!!!!!!!! Service you can't beat
Don't get all hung up in this one better than that one--the builders attention to bearings and such will have way more to do with good service life--No Detonation--timing correct--bearing clearences right for the application and away you go
Try King HP bearings for some happy measuring.
Good luck!

Re: Big block 4.150 stroke 2.375 rod 4340 crank? [Re: onyxba] #1712484
12/18/14 07:48 PM
12/18/14 07:48 PM
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Stuttgart, Arkansas
rickseeman Offline
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Quote:

What crank would you run, eagle, scat, molnar. ohio crank. Drag race 750 to 800 horsepower? Thanks for any reply's.




I assume they are all made by the same 12 year old girl in China. And I assume any of them would be fine for your application.


2011 Drag Pak Challenger
Re: Big block 4.150 stroke 2.375 rod 4340 crank? [Re: rickseeman] #1712485
12/18/14 08:17 PM
12/18/14 08:17 PM
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dogdays Offline
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Go to www.wiseco.com Click on the K1 clearance section. Find the 4.25" stroke forged crank for $400.

That's a screaming deal.

R.

Re: Big block 4.150 stroke 2.375 rod 4340 crank? [Re: rickseeman] #1712486
12/18/14 08:17 PM
12/18/14 08:17 PM
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Quote:

Quote:

What crank would you run, eagle, scat, molnar. ohio crank. Drag race 750 to 800 horsepower? Thanks for any reply's.




I assume they are all made by the same 12 year old girl in China. And I assume any of them would be fine for your application.




to a degree I agree but I would go with the Molnar .

As dogdays mentioned , your bigger concern is the BLOCK ...

Re: Big block 4.150 stroke 2.375 rod 4340 crank? [Re: JohnRR] #1712487
12/18/14 08:27 PM
12/18/14 08:27 PM
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Vidor Texas
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onyxba Offline OP
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block is a mopar mega block cross bolted mains. using a milodon dual line oiling system. We have lost # 6 rod bearing 2 times. clearance rods .0028 main.0032 feel we are jinxed on this one. The crank has no name on it so don't know what brand it is. Looking for options on new crank. Thanks for the replys. Current rod are carillo sshemi rods.

Last edited by onyxba; 12/18/14 08:29 PM.
Re: Big block 4.150 stroke 2.375 rod 4340 crank? [Re: dogdays] #1712488
12/18/14 09:43 PM
12/18/14 09:43 PM
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Romulus, MI
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Quote:

Go to www.wiseco.com Click on the K1 clearance section. Find the 4.25" stroke forged crank for $400.

That's a screaming deal.

R.




That particular crank is 6 bolt flange and has 2.375 rod journals. It was actually $363 when I ordered one about a month ago. At that time I got one of the 2 that were still available.

Re: Big block 4.150 stroke 2.375 rod 4340 crank? [Re: onyxba] #1712489
12/18/14 10:22 PM
12/18/14 10:22 PM
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Bend,OR USA
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I quit using the 2.375 Mopar rod journal size stroker cranks about ten years ago, maybe you should to The smaller I.D. diameter rod bearings don't travel as far per revolution as the larger ones do Another plus in my mind is the lighter recripocating weight and less stress at the same RPM from the lighter rods As far as tight rod bearing clearances like your using I would open them up to at least .0030 or bigger, same thing on the mains, try .0035 or larger When the same components fail time after time there is usually a reason for it, the hard part is figuring out what is causing it What brand and part number rod bearings are you using?What type of rods. aluminum or steel? How about oil pressure hot at the upper RPM and weight of oil BTW, what RPM are you using as the shift RPM in each gear and at the finish line? #6 rod journal gets its oil from #4 main bearing, if your using the stock type internal oiling to the rocker shafts the oil for those comes out of the #4 main also


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Big block 4.150 stroke 2.375 rod 4340 crank? [Re: onyxba] #1712490
12/19/14 12:39 AM
12/19/14 12:39 AM
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Oregon
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Have you run a reamer thru all of the oil passages? It is very easy for one oil passage to be restricted. I've lost rod bearings for that reason before.

Re: Big block 4.150 stroke 2.375 rod 4340 crank? [Re: AndyF] #1712491
12/19/14 11:11 AM
12/19/14 11:11 AM
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Quote:

Have you run a reamer thru all of the oil passages? It is very easy for one oil passage to be restricted. I've lost rod bearings for that reason before.



My first thought was oiling problems. Molner has the best rep of the three IMHO. Great guy to deal with as well.


8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
Re: Big block 4.150 stroke 2.375 rod 4340 crank? [Re: ] #1712492
12/19/14 11:16 AM
12/19/14 11:16 AM
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Val-haul-ass... eventually
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Quote:

... the Eagle has been refined over the years and is a very good unit...



All I can add to this comment is that Dwayne Porter (Porter Racing Heads) had mentioned a couple of years ago that the last Eagle cranks he'd had were good w/o having to have "correction re-grinds", and that all the journals on the Eagle 3.75"-stroke 6-bolt I crank bought after that measured OK, too.

Scat's stuff has a good reputation, but seem priced a lot higher than what I think the comparable cranks on the market are.

If I was collecting parts from scratch today, I'd look into the 2.200" rod journal option, too. I'd also give the Molnar stuff some serious consideration, if Tom M. has one that fits my combination.

Re: Big block 4.150 stroke 2.375 rod 4340 crank? [Re: Cab_Burge] #1712493
12/19/14 01:09 PM
12/19/14 01:09 PM
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onyxba Offline OP
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Thanks to all who responded. 1st engine referred with my brother bearing clearances were .003 rods and .003 mains, I thought what I wrote correct so I asked him, he checked notes on build and these were the clearances. rod bearings were calico CB663hndbx4. Rods are carillo steel CR426ss. Shift at 7000 and go through the 1/8 at 6400. 440 source oil pan with drag link through pan 10 quarts 15w40 rotella, wix racing filter.Oil pressure at idle hot 60 to 65. Don't know what oil pressure is at end of pass, my friend who's car it is hasn't got comfortable driving the car enough to look at gauges for that information. 2nd go around clevite cb527p bearing. That bearing in clevite was all we could find at .030 rod bearing. Clearances on this were .0035 rod .0030 mains. The engine has 440-1 heads so oil to the top end is oiled externally with 1 60 holly jet feeding both heads. All other bearings in great shape, even #7 which you know is fed off of #4 main. This block is supposed to be priority main oiling so if there are any oil mods to this block, I would greatly appreciate any advice. Thanks again to all help.

Re: Big block 4.150 stroke 2.375 rod 4340 crank? [Re: onyxba] #1712494
12/19/14 02:43 PM
12/19/14 02:43 PM
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Quote:

Thanks to all who responded. 1st engine referred with my brother bearing clearances were .003 rods and .003 mains, I thought what I wrote correct so I asked him, he checked notes on build and these were the clearances. rod bearings were calico CB663hndbx4. Rods are carillo steel CR426ss. Shift at 7000 and go through the 1/8 at 6400. 440 source oil pan with drag link through pan 10 quarts 15w40 rotella, wix racing filter.Oil pressure at idle hot 60 to 65. Don't know what oil pressure is at end of pass, my friend who's car it is hasn't got comfortable driving the car enough to look at gauges for that information. 2nd go around clevite cb527p bearing. That bearing in clevite was all we could find at .030 rod bearing. Clearances on this were .0035 rod .0030 mains. The engine has 440-1 heads so oil to the top end is oiled externally with 1 60 holly jet feeding both heads. All other bearings in great shape, even #7 which you know is fed off of #4 main. This block is supposed to be priority main oiling so if there are any oil mods to this block, I would greatly appreciate any advice. Thanks again to all help.




.0035 rod clearance to start, isn't that a little much ?

Also you said you have a MEGA BLOCK, is it a MEGABLOCK or a WORLD block ? World has priority main oiling, Megablock does not.







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